Strip spaces before/after parenthesis inside generator expression

python/src/com/jetbrains/python/formatter/PythonFormattingModelBuilder.java

@@ -113,6 +113,7 @@ public class PythonFormattingModelBuilder implements FormattingModelBuilderEx, C
       .withinPairInside(LPAR, RPAR, ARGUMENT_LIST).spaceIf(commonSettings.SPACE_WITHIN_METHOD_CALL_PARENTHESES)
       .withinPairInside(LPAR, RPAR, PARAMETER_LIST).spaceIf(commonSettings.SPACE_WITHIN_METHOD_PARENTHESES)
       .withinPairInside(LPAR, RPAR, FROM_IMPORT_STATEMENT).spaces(0)
+      .withinPairInside(LPAR, RPAR, GENERATOR_EXPRESSION).spaces(0)
       .before(LBRACKET).spaceIf(pySettings.SPACE_BEFORE_LBRACKET)
 
       .withinPair(LBRACE, RBRACE).spaceIf(pySettings.SPACE_WITHIN_BRACES)

python/testData/formatter/parenthesisAroundGeneratorExpression.py

@@ -0,0 +1 @@
+gen = (    for c in 'abrakadabra'  )

python/testData/formatter/parenthesisAroundGeneratorExpression_after.py

@@ -0,0 +1 @@
+gen = (for c in 'abrakadabra')

python/testSrc/com/jetbrains/python/PyFormatterTest.java

@@ -404,6 +404,10 @@ public class PyFormatterTest extends PyTestCase {
     doTest();
   }
 
+  public void testParenthesisAroundGeneratorExpression() {
+    doTest();
+  }
+
   private void doTest() {
     doTest(false);
   }